Facebook takes on Tinder with new dating service for 'real, long-term relationships'

Speaking in San Jose, California, at the F8 gathering of software developers, tech folks and others, Zuckerberg said to cheers that the company is re-opening app reviews, the process that gets new and updated apps on its services.

"The hardest decision I made wasn't to invest in safety and security", Zuckerberg said.

Geoff Blaber, vice president of research and market analysis firm CCS Insight, says that by leading off the conference with a focus on security and privacy, but pledging the only way to overcome those challenges is to continue to build services, Zuckerberg successfully "walked the tightrope".

"We are taking a broader view of our responsibility - to not only give people powerful tools but to make sure these tools are used for good". There are 200 million people who have marked themselves as single on Facebook, he said. It turns out one of those things is a competitor for apps like Tinder and Hinge, although he emphasized the intent to build long term relationships, and "not just hookups".

Facebook separately announced Tuesday that its popular Messenger app would soon be able to translate missives in real time, deploying artificial intelligence to enable text conversations between people using different languages. Their regular friends won't see these profiles.

"It mirrors the way people actually date, which is usually at events and institutions that they're connected to", Chief Product Office Chris Cox said during the F8 conference. The service, now under development, is called Clear History, and it will allow Facebook users to see the websites and apps that use Facebook data gathering tech (e.g. the Like button) and to clear the analytics data they send back to the mothership. Instagram is also getting video chat and a redesigned Explore tab.

The social network unveiled a new feature on its fast-growing Instagram photo-sharing app, which has been a bright spot amid the recent turmoil at Facebook.

On Tuesday morning, Facebook also suddenly began offering users an option to flag every post in News Feeds and elsewhere as hate speech.

Zuckeberg was cheerful and even giggly at times during his presentation, a far cry from his stiff testimony two weeks ago in front of Congress.

Mr. Zuckerberg may be traveling overseas to speak with members of the European Parliament this month, Politico reported last week, and Mr. Collins' committee "would like Mr. Zuckerberg to come to London during his European trip", his letter said.

Officials in the United Kingdom and US have opened inquiries into Facebook and its privacy policies after it was revealed in March that Cambridge Analytica, a British-based political consulting firm, had amassed the personal information of 87 million Facebook users without their permission.